Trunk and Upper Limb Muscle Activation During Flat and Topspin Forehand Drives

[julian]

J Appl Biomech. 2011 Feb;27(1):15-21.
Trunk and upper limb muscle activation during flat and topspin forehand drives in young tennis players.
Rogowski I, Rouffet D, Lambalot F, Brosseau O, Hautier C.
Source

Université de Lyon, Lyon, France.
Abstract

This study compared EMG activity of young tennis players' muscles during forehand drives in two groups, GD-those able to raise by more than 150% the vertical velocity of racket-face at impact from flat to topspin forehand drives, and GND, those not able to increase their vertical velocity to the same extent. Upper limb joint angles, racket-face velocities, and average EMGrms values, were studied. At similar joint angles, a fall in horizontal velocity and a rise in racket-face vertical velocity from flat to topspin forehand drives were observed. Shoulder muscle activity rose from flat to topspin forehand drives in GND, but not for drives in GD. Forearm muscle activity reduced from flat to topspin forehand drives in GD, but muscle activation was similar in GND. The results show that radial deviation increased racket-face vertical velocity more at impact from the flat to topspin forehand drives than shoulder abduction.

 

[RetroSpin]

Very interesting.

Does this also mean that you should approach impact in ulnar deviation? The signature ATP FH move, the laid back racquet as you start forward from PTD, does put you in UD.

 

[Ash_Smith]

This combined with previous studies would lead us to believe that for optimum racquet head speed we should approach the ball with the wrist in extension and ulnar deviation and move through flexion (but not past neutral) and radial deviation into and through contact. Not, as has been previously though and widely taught to maintain the wrist extension through contact.

 

[RetroSpin]

Ash,
Do you believe that is the optimal technique? I think high speed vids of top pros show that there is some minor movement from max extension prior to contact, but the move to neutral wrist occurs after contact. There seems to be some belief that extension is adjusted for directional control, not power.

 

[Ash_Smith]

^^^I think it will depend on the individual and also on the hitting structure of the arm. Toly (i think) had some examples whereby the contact had the wrist neutral, others where the wrist was still in slight extension.

 

[LeeD]

I hit a flatter groundie with late contact.
I hit more topspin with an early contact point.

 

[toly]

^^^I think it will depend on the individual and also on the hitting structure of the arm. Toly (i think) had some examples whereby the contact had the wrist neutral, others where the wrist was still in slight extension.

I hit a flatter groundie with late contact.
I hit more topspin with an early contact point.

Verdasco hits with almost maximum wrist ulnar deviation, but Fish with practically neutral wrist ulnar/radial deviation and some the wrist extansion. Due to these wrist actions Verdasco have to meet the ball later than Fish. BTW, Verdasco produces flat and Fish topspin forehand. :shock:

 

[LeeD]

Early or late contact point is reflected in preference and grip of the player. And of course, the wrist position at contact.

 

[RetroSpin]

Here's Verdasco hitting with wrist extension. http://1.bp.blogspot.com/-qKCLOgBMVdM/UR5oVIiM06I/AAAAAAAAAgo/7DXBE-XKaok/s1600/FV+v+EG.jpg

To be fair, there are other shots of him hitting with neutral wrist.

 

[julian]

Speed of a ball vs wrist extension

Seeley MK, Find all citations by this author (default).Or filter your current search
Funk MD, Find all citations by this author (default).Or filter your current search
Denning WM, Find all citations by this author (default).Or filter your current search
Hager RL, Find all citations by this author (default).Or filter your current search
Hopkins JT
Brigham Young University, Provo, UT 84602, USA. matt_seeley@byu.edu
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Sports Biomechanics / International Society of Biomechanics in Sports [2011, 10(4):415-426]
Type: Journal Article
Abstract Highlight Terms
No biological terms identified
Peak joint angles and joint angular velocities were evaluated for varying speed forehands in an attempt to better understand what kinematic variables are most closely related to increases in post-impact ball velocity above 50% of maximal effort. High-speed video was used to measure three-dimensional motion for 12 highly skilled tennis players who performed forehands at three different post-impact ball speeds: fast (42.7 +/- 3.8 m/s), medium (32.1 +/- 2.9 m/s), and slow (21.4 +/- 2.0 m/s). Several dominant-side peak joint angles (prior to ball impact) increased as post-impact ball speed increased from slow to fast: wrist extension (16%), trunk rotation (28%), hip flexion (38%), knee flexion (27%), and dorsiflexion (5%). Between the aforementioned peak joint angles and ball impact, dominant-side peak angular velocities increased as ball speed increased from slow to fast: peak wrist flexion (118%), elbow flexion (176%), trunk rotation (99%), hip extension (143%), knee extension (56%), and plantarflexion (87%). Most kinematic variables changed as forehand ball speed changed; however, some variables changed more than others, indicating that range of motion and angular velocity for some joints may be more closely related to post-impact ball speed than for other joints.